7 Symptoms of a Bad Fuel Injector in Your Car
Modern internal combustion engines operate on a precisely regulated ratio of air to fuel. Fuel is delivered to the combustion chamber in very specific quantities through components called fuel injectors.
What are fuel injectors?
Fuel injectors are electronic controls that spray a fine mist of fuel under high pressure. The process by which liquid fuel is converted into this fine mist is called atomization. Fuel injectors work similarly to small electronically controlled injection bottles. Fuel injectors inject fuel at pressures ranging from 30 psi (2 bar) to several thousand psi (hundreds of bar), depending on the engine and injection type.
Injectors can be located either in the throttle body (throttle body injection), the intake manifold (port injection), or in the combustion chamber itself (direct injection).
Some newer vehicles are equipped with injectors in both the intake port and the combustion chamber. This is called dual injection. Toyota is a manufacturer that uses dual injection engines.
Injectors can fail for a variety of reasons. In this list, different failures will have different symptoms, but there may be some overlap.
A clogged injector can make it difficult to atomize fuel. A clogged injector can cause reduced flow, liquid fuel to drip into the combustion chamber, or the injector may not inject fuel at all. Injectors can also leak, allowing liquid fuel to get into the combustion chamber when the injector should be closed. Electrical problems can cause the injector to fail to fire at all. In all of these cases, one or more of these symptoms can occur:
1) Engine misfire/rough idle
Engine misfires can be caused by many component defects, but one of those components is a defective fuel injector.
Misfires can occur when an injector is clogged, leaking, or not firing. When an injector fails, it will feel like the cylinder is not delivering power. This can cause a rough or erratic idle.
If you suspect that an injector is not working, there’s an old method that can help you determine if all of your injectors are working properly.
Assuming you have access to the injectors, grab a flat-head screwdriver. Hold the handle to your ear and place the tip of the screwdriver against the injector. While the engine is running, the driver will hear a rhythmic clicking sound. This clicking sound probably means that the injector is firing.
If you notice that only one cylinder does not make this clicking sound, the injector is more likely to be defective. You will probably also need to test the electrical connections of this injector.
Your factory service manual will have information about the expected voltages for each pin, so you can be sure that the problem is indeed with the injector and not the wiring. Another quick test is to replace the injector you suspect is defective with one that makes a clicking noise. If you no longer hear the noise after the injector fails, you know the cause is the injector itself. If the noise doesn’t come from the original cylinder, start troubleshooting the electrical system before replacing the injector.
2) Check the engine light
Engine misfires often bring on the check engine light, but there can be a variety of reasons that the check engine light will come on.
Before you get too deep into troubleshooting or calling for help, scan for codes to see what the ECU thinks is wrong. This will narrow down the problem significantly. Often the codes can be scanned for free at your local auto parts store.
If a misfire code appears, replace the spark plugs and spark plug wires (or ignition coil) for the other cylinder. When doing any type of diagnosis or troubleshooting, it’s always a good idea to start with the least expensive and easiest procedure first. Spark plugs are easier to replace than fuel injectors on most cars.
If a misfire in another cylinder has caused a new Check Engine Light to come on, replace the spark plugs. Repeat this process with the injector. You may have to drive your car for a while until a new check engine light comes on.
3) Starting Problems
If you are having trouble starting your car, a leaking injector could be causing a cylinder to flood. If one or more fuel injectors are defective, your vehicle may have difficulty starting because these cylinders will not produce power.
This is a less common issue, but defective fuel injectors can make your car difficult to start. 4) Poor Fuel Economy
Leaking fuel injectors can also cause fuel to drip into the engine at the wrong time in the combustion cycle. This is a waste of fuel as it does nothing to improve performance.
You will probably notice a significant decrease in fuel consumption. You may also notice other symptoms on this list if you have a leaking fuel injector.
5) Poor Performance
If one or more cylinders are not achieving the target air-fuel ratio, your engine is most likely not making as much power as it did when it left the factory.
If you notice a decrease in performance, look out for other symptoms on this list, such as: B. Poor fuel economy, rough idle. This may indicate a problem with the injectors.
6) Engine Surge
Intermittent faults are the most difficult type of fault to diagnose. If an injector is partially clogged, it may cause a sudden increase in engine power as it fails even though the injector is working properly.
Injectors can be cleaned and tested using special equipment. If you’re interested, a quick search online can help you find companies that offer fuel injector cleaning or testing services. 7) Fuel Leaks
If you smell fuel in the engine bay or notice a damp spot around the fuel rail, you may have a leaking injector. Manifold injectors have an O-ring that seals against the intake manifold.